docs: def floatformat(fmt_string):
      """
      Context manager to change the default format string for the
      function :func:`openquake.commonlib.writers.scientificformat`.
  
      :param fmt_string: the format to use; for instance '%13.9E'
      """
      fmt_defaults = scientificformat.__defaults__
      scientificformat.__defaults__ = (fmt_string,) + fmt_defaults[1:]
      try:
          yield
      finally:
          scientificformat.__defaults__ = fmt_defaults